Water Germination of Showy Milkweed Seeds

In this test seeds of Asclepias speciosa (showy milkweed) were used. The seeds were collected in the fall of 2017. Under normal conditions the seeds would have fell to the ground in September. Their tough exterior would have been exposed to the weather during the winter. Snow and rain would have stratified the seed and prepared them to grow in the late spring.

The seeds being tested have not lived a normal life. These seeds were collected from ripe opening pods on top of milkweed plants that were beginning to go dormant after a long hot summer. After being collected they were separated from their seed pod and the milkweed silk that could have carried them thru the air. The seeds are dried for a few weeks in the open air and then stored in open bags indoors.

To be fair, nature does a pretty good job. Milkweed has been growing for thousands of years without any human intervention. On the other hand, one milkweed plant can cast out thousands of seeds and only a tiny fraction of those seeds will find the right conditions to grow. Milkweed seeds do benefit from Cold Moist Stratification which can be simulated in the refrigerator. It takes time to cold moist stratify milkweed seeds and may not be necessary. What if there is a faster way that works?

Day One

2/11/18 21:00 water temp was 63° based on infrared thermometer. Drained water off plate (dropped half the seeds in the sink). Put seeds back and added dechlorinated water. Placed heat mat under plate. Water temp at 22:00 is 70°

26 showy milkweed seeds

Day Two

2/12/18 09:00 drained water off plate. Added fresh dechlorinated water. Placed plate on the heating mat. Water temp at 10:00 is 74°

2/13/18 01:00 drained water. Added water. 74°

Day Three

2/13/18 13:00 drained water off plate. Two seeds are showing growth. Added water. Placed plate on heating mat. ​2/14/18 01:00 drained water. Added fresh water. Placed plate with seeds on heating mat. At least six of twenty six seeds are growing. Water is 75° at 02:00

germination begins at day three

Day Four

2/14/18 13:00 eight seeds are showing growth. Drained water. Added water. Back on heating mat. Water back to 75° at 14:00

Day Five

2/15/18 10:00 Five days since test began. Exactly 50% of showy milkweed seeds have germinated. 13 growing 13 not growing.

2/15/18 10:30 clipped the tip of the 13 ungerminated seeds and placed them in a new coffee filter in dechlorinated water on a plate on a heating mat. A plastic dome was placed over everything and the temp is now 80°-85°

2/16/18 00:45 added water to plate. Dome created higher temp which evaporated most of the water.

Day Seven

Findings

Within 5 days 50% of the seeds germinated. Thats 13 of 26 seeds growing in five days. Clipping of the 13 ungerminated seeds was done at the end of 5 days. The 13 newly clipped seeds germinated at a rate of 62% after two additional days. That means 8 ofthe 13 slow to germinate seeds did end up growing after clipping occurred Total germination of the 26 seeds was 21 seeds or 80.7%

Showy milkweed seed packet, Asclepias speciosa (hand collected)

Water Germination of Common Milkweed Seeds

Water germination of showy milkweed seeds worked very well. 80% of the showy milkweed seeds germinated in seven days. I am repeating the test with common milkweed seeds.

When you ask the internet "how to grow common milkweed?" you will almost always be provided directions to Cold Moist Stratification of Milkweed Seeds. Does it work? Yes. Is there a faster way that works? Lets find out.

26 common milkweed seeds

Water Germination of Showy Milkweed Seeds worked and you can read about that at the beginning of this blog post. I'm in the process of testing the method using common milkweed seeds. The results will be updated as they become available. As you can see in this photo the common milkweed seeds are in a coffee filter. The coffee filter is placed on a lunch plate. Dechlorinated water is poured onto the plate so the seeds are fully submerged. The plate is placed on top of a seedling heat mat. A plastic bin is placed over everything. The temperature of the water is measured with an infrared thermometer. Current temperature is 80 degrees Fahrenheit Try to keep the seeds between 75 degrees and 85 degrees. Latest update 3/6/2018

water germination of common milkweed seeds

Day One

Day one requires an initial setup. Place the seedling warming mat on a table and plug it in. Set a plate on the seedling warming mat. Hopefully the day before this you have left water out for twenty four hours so it is now dechlorinated water. Pour the water into the plate. Place the milkweed seeds in the coffee filter. Set the coffee filter on the plate so the seeds are completely submerged in water. Water temperature should be 75 to 85 degrees.

Day One Video

Day Two

Clipping the milkweed seed will speed up water germination. The seeds can be clipped before going in the water but I like to wait twelve to thirty six hours before clipping the seeds. Letting them absorb some water in the first day makes them softer and easier to clip.

Day Two Video

Day Three

Water change twice per day. Two of the twenty six seeds have root beginning to show from the seed.

Day Four

At day four there were ten seeds beginning to grow. Sixteen seeds are not showing any signs of germination. At this point I was still expecting more of the seeds to grow over the next few days. That did not occur. All the growth began in fewer then five days. The best thing to do with the common milkweed seeds that are not growing is to place them into cold moist stratification.

Findings

The test continued to day seven. The length of the seeds roots increased but the ungerminated seeds did not germinate. The method is effective in germinating common milkweed seeds. Only some of the viable seeds seem ready to grow. I would like to guess then cold moist stratification prior to water germination could increase the germination rates of the common milkweed seed.

Water Germination of Whorled Milkweed Seeds

The whorled milkweed seeds I am working with this week have a verified germination rate of 93%. The goal is to start these seeds growing in less then a week. The test began with thirty whorled milkweed seeds.

Day One Thru Three

Seeds were dropped into a clear plastic cup. Dechlorinated water was poured into the cup to a depth of 1 centimeter. The cup was placed on aseedling warming mat. The water was drained from the cup and replenished twice each day. At the end of the third day there were two seeds germinating.

Day Four

Continue to drain and replenish the water twice per day. At day four there are a total of six seeds germinating in the bottom of the cup. The cup has always been siting on top of the *seedling warming mat.

Testing of whorled milkweed continued until seven days elapsed.

Findings

At day seven the seeds were removed from the cup of water, untangled, and counted. The results were extremely rewarding. Seventeen seeds are growing and thirteen seeds did not grow. The germination rate is 56% in only seven days. While the germination rate did not reach the ideal number of 93% the results are considered successful. In addition to the number of seeds that germinated I was very surprised to see how long the roots had grown and how vigorous the seedlings appeared to be. When the outdoor weather becomes suitable for growing I will plan to water germinate many more whorled milkweed seeds.

Whorled milkweed seed packet, Asclepias verticillata

Water Germination of Mexican Whorled Milkweed seeds

This test began with thirty mexican whorled milkweed seeds. The seeds were placed in a cup and water is added to one centimeter in depth. Twice each day the water was drained and replenished. At day two there was one seed growing and twenty nine were not. At four days there were seven seeds growing and twenty three were not. The test continued for a total of six days.

Findings

At the end of day six there were seven seeds germinated. The test concluded. The germination rate in water of the initial thirty seeds was 23%. Seven seeds grew and twenty three seeds did not germinate. The seeds that did sprout grew very long and healthy looking roots. I decided to plant the roots in a bit of soil. The outdoor temperature is not conducive to growing milkweed seedlings in March. I have placed the plants in soil in a red solo cup with drainage holes. They remain on the seedling warming mat on my kitchen counter. I'll try to provide an update as far as if they survive or die. I'm not very optimistic because I continue to have problems growing mexican whorled milkweed despite how well it seems to grow all around me.

Mexican whorled milkweed seed packet, Asclepias fascicularis

Water Germination of Milkweed tree seeds

These are new seeds for Brad Grimm dba Grow Milkweed Plants in 2018. I traveled to the Rio Grande Valley to see the plant that produced these seeds. Oleander Seth at Oleander Acres was kind enough to sell me a few of these wonderful seeds. One of the first seed packets was sent to a customer who had wonderful results using water germination for her first time. Seeing the customers fantastic results I decided to sprout seeds myself. This test began on November 8, 2018 with only three Calotropis procera seeds. The seeds were placed in a clear plastic cup and water was added to one centimeter in depth. Twice each day, at twelve hour intervals, the water was drained and replenished. I added warm to hot tap water. At one and a half days (36 hours) there was two seeds with root radicals beginning to show. (see photo below)

two root radicals after 36 hours

Okay, so that was fast! Following the water germination method is working well. The seeds continue to get fresh warm tap water and remain on the seedling warming mat. At day two (48 hours) the two seeds have longer root radicals. (see photo below)

growth from Calotropis procera after 48 hours

Obviously it would be nice to seed all three seeds sprout. It just takes a little more time. At just under three days (70 hours) all three seeds have sprouted. This is when the fun begins.

These Milkweed tree seeds have made me feel like a real green thumb gardener. I should say that sprouting seeds in November isn't the best time of year because the sun is low in the sky and the outdoor temperature frequently drops below freezing here in northern Nevada. The Milkweed tree is a tropical and sub tropical plant so it will never live year round in its current location. Fortunately it can be grown in containers and that is the next step.

A wonderful advantage of starting seeds by water germination is how easy it it to plant the seeds. All I did was clean a container that previously has annual flowers that had perished in the recent freezes. I added a soilless base in the container to assist in facilitating the capillary action to wick water from the built in saucer. In the bottom of the planter I used a Coco Coir Brick. Then I added FoxFarm Strawberry Fields Potting Soil.

planting seeds on day 3

Here is the great part. Planting is as easy as dumping the seeds right from the cup into the soil. All I did now was pour out the seeds and water onto the surface of the soil. I was careful to move the cup while pouring. I wanted the seeds to have separation. A simple circular motion was all that it took. One of the seeds didn't immediately pour out so I added more water to the cup and poured the last seed onto the soil a few inches away from the other two seeds. I've been keeping the planter on the seed warming mat and adding water to the planters saucer.

Today is day nine since the seeds started. Seeds have been in the soil for six days. All three seeds were only lightly settled in the soil. They have now pushed their way above the soil. Based on my germination combined with Jessalyn's germination results. The seeds are at 96% germination.

Milkweed tree, Calotropis procera 19 seeds

Common names include Sodom's Apple, Dead Sea Apple, Rooster Tree, Rubber Bush and Milkweed tree. Zone 10-11 plant will like special treatment in colder zones during winter. Can be grown in an island (container),

Water Germination of Butterfly Weed Seeds

Day One

Thirty butterfly weed seeds placed in a cup of shallow water. Placed cup on seedling warming mat. Water changed with fresh water after twelve hours.

Day Two

Water changed with fresh water twice on day two.

Day Three

Water changed with fresh water twice on day three.

Day Four

Water changed with fresh water twice on day three.Durring the second water change twenty seven of the thirty seeds were growing.

Day Five

At the beginning of day five all thirty seeds were growing. 100% germination of thirty seeds in five days.

Butterfly weed seeds

Butterfly weed seeds

Findings

WOW! Water germination of butterfly weed worked great. I've never seen 100% germination before. Results are not typical. These seeds in the test are no longer available but they were great while they lasted. Plants from these seeds are growing in my garden. When they produce seeds I'll make them available on this site.

Butterfly weed seed packet, Asclepias tuberosa (hand collected)

Water Germination of Sand MilkWeed Seeds

Day One through Day Five

Thirty Sand milkweed seeds placed in a cup of shallow water. Placed cup on seedling warming mat. Water changed with fresh water after twelve hours. Water changed every twelve hours for five days. At the beginning of the fifth day six seed were growing.

Day Six Through Day Eight

Water changed with fresh water every twelve hours. On the beginning of day eight ten seeds were growing. The ten growing seeds were planted.

Day Nine Through Day Eleven

Water changed with fresh water every twelve hours. The water germination test concluded on day eleven. Eleven seeds grew.

Findings

Eleven of thirty sand milkweed seeds grew. The germination rate is 36%. The seeds were from Prairie Moon Nursery and they told me the germination rate of these seeds was 25%. Therefore water germination of sand milkweed appears to work better then whatever method was used in their germination test.

Sand milkweed seed packet, Asclepias arenaria

Water Germination of Heartleaf MilkWeed Seeds

Day One Through Day Nine

Thirty Heartleaf milkweed seeds placed in a cup of shallow water. Placed cup on seedling warming mat. Water changed with fresh water after twelve hours. Water changed every twelve hours for nine days. On day five i scraped the tip of five seeds with a sharp knife to remove part of the seeds exterior near where the root radical grows from. On day nine I clipped the tip of the other twenty five seeds with tweezers.

Water Germination of Desert Milkweed Seeds

Highly successful! Water germination of these desert milkweed seeds was very quick and easy. The seeds began sprouting on the second day and all fourteen of the seeds that grew were growing by day three.

One seeds didn't grow at all. The sample size was small only fifteen seeds. Overall I got 93% germination. After getting sprouts in three days I continued the water germination process thru day five.

On the fifth day I planted the seeds in soil. I made a video of the process. Be sure to Subscribe, Like and Share the video.

Desert milkweed seeds July 2018

Desert milkweed plants August 2018

Pro tip. Asclepias erosa grows a massive taproot when mature. This allows it to be a great plant thru the dry hot summers in the southwest. Be aware that the small root is very brittle and a great deal of care needs to be taken while handling and planting the seedling. A broken root can kill the fragile plant.